Why won't my phone receive messages?

I have a Samsung Galaxy lite and at random points in the day, my phone will not receive messages and I will constantly have to restart my phone, and messages will start
pouring in.... Anyone know why it is doing this, or know how to solve this problem?

It may also pay to bring the phone into the carrier. It could be flaky provisioning in your account (what they have in their database), it could, as Belodion said, be a flaky SIM card, it could be that your carrier is having an SMS problem - there are too many possibilities to help you by listing them all.